A control system configured to control a deceleration process of an air vehicle which comprises at least one tiltable propulsion unit, each of the at least one tiltable propulsion units is tiltable to provide a thrust whose direction is variable at least between a general vertical thrust vector direction and a general longitudinal thrust vector direction with respect to the air vehicle.

In some embodiments, an aircraft includes a flying frame having an airframe, a propulsion system attached to the airframe and a flight control system operably associated with the propulsion system wherein, the flying frame has a vertical takeoff and landing mode and a forward flight mode. A pod assembly is selectively attachable to the flying frame such that the flying frame is rotatable about the pod assembly wherein, the pod assembly remains in a generally horizontal attitude during vertical takeoff and landing, forward flight and transitions therebetween.

In one aspect, there is a method of making a composite skin for a tiltrotor aircraft including providing a first skin in a mold, the first skin having a periphery defined by a forward edge, an aft edge, and outboard ends; providing a plurality of honeycomb panels having an array of large cells onto the first skin, each cell having a width of at least 1 cm; assembling the plurality of honeycomb panels along the longitudinal axis of the first skin to form a honeycomb core having an outer perimeter within the periphery of the first skin; positioning a second skin onto the honeycomb core, the second skin having an outer perimeter within the periphery of the first skin; and curing an adhesive to create a bond between the first skin, the honeycomb core, and the second skin to form a composite skin.

An aircraft having a vertical takeoff and landing fight mode and a forward flight mode. The aircraft includes an airframe and a versatile propulsion system attached to the airframe. The versatile propulsion system includes a plurality of propulsion assemblies. A flight control system is operable to independently control the propulsion assemblies. The propulsion assemblies are interchangeably attachable to the airframe such that the aircraft has a liquid fuel flight mode and an electric flight mode. In the liquid fuel flight mode, energy is provided to each of the propulsion assemblies from a liquid fuel. In the electric flight mode, energy is provided to each of the propulsion assemblies from an electric power source.

According to at least one exemplary embodiment, a method, system and apparatus for an aircraft may be shown and described. An exemplary embodiment may be an autonomous aircraft which can vertically takeoff and land (VTOL). The VTOL aircraft may have a modular pod which carries a removable payload. The entire VTOL aircraft may be portable. An exemplary embodiment may fit into a standard sized freight container. A propulsion system may be based on distributed electric propulsion. An exemplary embodiment may implement variable pitch propellers and collective pitch variation.

A modular battery system provides propulsive power to the rotor system of an aircraft. The modular battery system includes an array of battery modules arranged in at least one stack. Each battery module includes a plurality of battery cells, a first side having positive and negative receptacles and a second side, that is opposite of the first side, having positive and negative plugs. The receptacles and plugs are configured such that adjacent battery modules in a side-by-side relationship are electrically coupled together via plug and receptacle connections and such that the battery modules are electrically coupled together in parallel. An interconnection electrically couples each stack of battery modules together via plug and receptacle connections with one of the battery modules in each stack such that the stacks of battery modules are electrically coupled together in parallel.

A propulsion assembly for a rotorcraft includes a raceway having a tapered inner surface and a mast configured to receive the raceway at a raceway receiving station. The mast has a tapered outer surface at the raceway receiving station. The propulsion assembly includes a mast bearing assembly having a plurality of bearings facing the mast to engage the raceway. The tapered inner surface of the raceway is friction welded to the tapered outer surface of the mast at the raceway receiving station to form a tapered friction weld line.

A first propeller has a shorter blade length and a lower inertia than a second propeller. An electromagnetic field emitter is coupled to one of the first propeller or the second propeller and an electromagnetic field receptor is coupled to the other one that is not coupled to the electromagnetic field emitter. The electromagnetic field emitter emits an electromagnetic field. In response to the electromagnetic field: the electromagnetic field receptor and its coupled propeller rotate in a first rotational direction; and the electromagnetic field emitter and its coupled propeller rotate in a second and counter-rotational direction. In response to a second electromagnetic field associated with increasing torque: the first propeller increases and subsequently decreases its rotational speed; and the second propeller increases its rotational speed at a slower rate than the increase in the rotational speed of the first propeller.

A rotor for an aircraft is described, comprising an input shaft rotatable around a first axis; an output member rotatable around a second axis; a coupling element functionally interposed between the input shaft and the output member and adapted to transmit the motion from the input shaft to the output member; the coupling element is configured to allow, in use, a fixed or variable inclination between the respective first and second axes; the coupling element comprises at least a first corrugated element made of an elastically deformable material; the first corrugated element allows the inclination through elastic deformation.

A vehicle includes a tilt rotor that is aft of a fixed wing and that is attached to the fixed wing via a pylon. A flight computer configured to instruct the tilt rotor to produce a maximum downward angle including by updating an actuator authority database associated with the flight computer to reflect the maximum downward angle, and generating a rotor control signal for the tilt rotor using the updated actuator authority database that reflects the maximum downward angle, wherein the maximum downward angle is adjustable.